Reduction of metallic bodies



Jilly'3l, 1934; P. STECKEL s r AL 1,968,790

'REDI-JGTION OF METALLIC BODIES Filed fla 4Q 1931 2 Sheets-Sheet 1INVENTORS l July 31, 1934. A. P. STECKEL ET AL I 1,968,790 v REDUCTION-QF METALLIC- BODIES Filed May 1931 2 Sheets-Sheet Patented July-31,-1934 UNITED STATES 1,968,790 REDUCTION or METALLIC BODIES Abram P.Steckeland Howard S. Lamb, Youngs I town, Ohio, assignors to The ColdMetal Process Company, Youngstown, Ohio, a corporation of OhioApplication May 4, 1931, Serial No. 535,030

28 Claims.

. This invention relates to. the reduction of metallic bodies and isparticularly directed to the 1 problem of gauging theamount ofreduction. It

is herein described as applied'to the cold-rolling 5 of strip metal in amill of the type illustrated in my Patent No. 1,744,018, dated January14, 1930, although it is applicable to the reduction of other metalbodies, for example, wire.

A wide variety of proposals have been made for the solution of theproblem of gauging the thickness of metal as it issues from a reducingmeans, such as a cold rolling mill. None of them have -provedsatisfactory. When the metal is travelling at high speed it is diflicultor impossible to directly measure its thickness with accuracy despitethe refinements which may be imposed in 'the measuring device. Variouselectrical circuits, usually employing amplifying" tubes, and supposedlyresponsive to variations in the thickness of the metal have also beenproposed, but these have not proved satisfactory in service.

We have found that the problem may be solved in a highly desirablefashion by an indirect process of measurement which involves themeasurement of the rate of elongation. In all metal rolling, with thepossible exception of the rolling of ingots wherein there are blow-holesto be closed off, the volume of the metallic body under treatment isconsidered to be constant. Therefore the cross sectional area multipliedby the length is a constant and, assuming the width to remain constant,the elongation is a measure of the reduction. While in certain classesof rolling and in certain-types of mills the metal widens during 35rolling, it is not inevitable that widening occur.

Onthe contrary, as shown by Patent No. 1,744,018,

the widening may be eliminated by using work rolls of sufiiciently smalldiameter. We provide for measuring the elongation of the material as ameans for determining the amount of reduction. This is particularlyaccurate in a mill where no widening occurs, but even if some wideningdoes take place, the method will be sufficiently accurate for suchclasses of product as are thereby produced.

We prefer to measure the entering and delivery speeds of the materialpreferably by driving mem bers such as sheaves or pulleys from the metalitself. We have employed the invention in connection with a cold rollingmill, such as illustrated in Patent No. 1,744,018, wherein the material.is ulled back and forth by means of reels through a pass consisting ofsmall work rolls backed by larger rolls having anti-friction mounting.The material in its passage from one reel to another is carried aroundcooling sheaves which properly aline the .material with the -roll pass.sheaves may be conveniently employed in carrying out the presentinvention. We prefer to drive reduction in accordance with the showingof the These wheels being connected to an indicator, one disc tending tomove the indicator in one direction, the other tending to move it in the.opposite direction. In a present preferred form the invention employs apair of coaxial discs with an indicator freely rotatable therebetwen.The indicator has a roller bearing against each disc. The discs aredriven by the entering and the delivered material, with compensationmade in the driving connection of one of the discs exactly to cQmDenSatefor the inevitable difference in speed of the entering and deliveredmaterial. This compensation is such that with a desired amount ofreduction the discs are traveling in opposite directions at the samespeed. Hence if the reduction actually being achieved is exactly equalto that which is desired, the indicator will remain stationary. However,even a slight departure from the desired amount of reduction will causea movement of theindicator. The device is particularly delicate becausethe effect of an improper rate of reduction is cumulative on the indicator and; since the movement of the indicator is in effect ameasurement of the increase in length of the material, much morepositive and 5 .accurate results can be attained than where attemptingto measure thicknesses direct, because the length dimension is on anorder of magnitude much greater than the thickness.

Provision is made for varying the amount 0 indicator. The connectionmay, if desired, be automatic, but for ordinary circumstances it may bemanual.

While the invention, as above stated, is preferably embodied in thestructure above briefly outlined, the essential principles may beemployed in various forms. As an example, an electric current may ,beemployed, the amount of current being proportioned to the relative speedof the entering and delivered material." This. however, whilesatisfactory for some purposes, is not as perfect as the embodimentabove outlined,

. for the electrical effect obtained may be due to an error of a givensize if the mill is delivering material at 1000 feet per minute, or itmay be due toan error say twice as great if the mill is deliverin'gmaterial at 500 feet per minute. In .short, such form of the inventiongives a result which involves the absolute speed of the material whichis not so in the preferred form. In certain cases, too, the speed of therolls may be employed as bearing a relationship to the delivered speedof the material. Ordinarily, however, I prefer to. apply directmeasuring devices to the material-after issuance from the mill.

In the accompanying drawings illustrating a present preferred embodimentof the invention, Figure 1 is a side elevation of a mill having themeasuringdevice appliedthereto; and

Figure 2 is a top plan view, largely diagrammatic, showing certainoperating parts of the mill of Figure 1.

The mill illustrated in Figure 1 comprises a housing 2 having reels 3and 4 adapted to be driven from a common power source, not shown, and tobe employed alternately for reeling and paying out the material. Theconnection of the reels with the power source is controlled by a lever5. Material being fed from, say, the reel 3 passes over a cooling sheave6 and thence'past wipers '7 and a guide 8 through work rolls 9. The workrolls are small undriven rolls which are backed by large diameter rolls10 mounted in anti-friction bearings 11. The issuing material passesover a cooling sheave 12 and thence to the reel 4. The upper backingroll 10 is adjustable vertically. Its bearings are carried in cases 13slidable in the housing and supported by spring balance mechanism 14.Wedges 15, adjustable laterally by hand wheels 16 and 17, determine thespacing of the work rolls 9 from one another.

The cooling sheave 6 is provided with ashaft extension 18 to which issecured a cone pulley 19, and the cooling sheave 12 is provided with,ashaft extension 20 to which is secured a cone pulley 21. The shaftextension 18 also carries a loose cone pulley 22 and between the opposedfaces 23 and 24 of the pulleys 19 and 22 there is arranged a spider 25having rollers 26 which engage such faces. The spider 25 also carriespointers 27.cooperating with a graduated arc 28 which is held in placeby brackets 29 secured to the housing 2 of the mill.

The pulleys 21 and 22 are connected by a crossed belt 30, which belt ispreferably a fine but strong cord or thread, such as silk fish line. Thepulleys are made very light in weight so as to have a minimumof inertiaeffect. The belt is kept taut by a belt tightener 31.

The shaft extension 20 also carries a pulley 32 which is loose thereonlike the pulley 22 and is connected to the pulley 19 by means of acrossed belt 33. The pulleys 21 and 32 are provided with a spider 25having a cooperating scale 28, as above described. It is intended thatthe pointer at one side 01' the mill shall be used when-the mill isbeing operated in one direction, and that the pointer at the other sideshall be used when it is operating in the other direction.

The proper amount of friction between the faces of the cone pulleys andthe pulleys 26 on the spiders is obtained by compression spring 34backed by collars 35 on the shaft extensions 18 and 20, the compressionsprings acting through anti-friction thrust bearings 36 to press thetight and loose pulleys together.

Now assume that material is being fed from the reel 3 to the reel 4, andthat a certain reduction, say, for example, a 10 percent reduction, isdesired. The steps of the cone pulleys are so arranged that the beltsmay be fitted into different grooves on the pulleys so that the pulley32 will run faster than the pulley 19 in amounts corresponding todifferent desired percentages of reduction'. In the case just given, ifit is a lo'percent reduction in thickness (and no variation in width)there will be a corresponding and definite elongation. Therefore, thecooling sheave 12 will run faster than the cooling sheave 6 in adefinite ratio. The belt 33 will therefore be placed in such grooves ofthe pulleys 19 and 32 as will speed up the pulley 32 to give it the samenumber of revolutions per minute as the pulley 21 makes. However, byreason of the fact that the belt 33 is crossed, the pulleys 21 and 32will be rotated in opposite directions. If the amount of reduction isexactly that desired, the peripheral speed of each of the pulleys 21 and32 at the point where it engages the rolls 26 will be the same, andtherefore the rollers 26 will rotate but their axes will not be movedaround the pointer 27 but will stand stationary. If, however, there iseven a slight deviation from the desired percentage, the pointer willbegin to move in one direction or the other, depending upon whether thereduction is greater orless than that which has been determined upon.Consequently, an adjustment of the pass must be made, as by adjustingthe screw-downs.

While material is being fed from the reel 3 to the 1'eel'4, theindicator at the right-hand side of the mill will be employed to checkthe reduction. It will not, however, be necessary to disconnect theindicator at the left-hand side. The pointer 27 .of this indicator willsimply rotate but will be disregarded. When the mill is driven inthereverse direction the belt 30 will be placed in the proper pulleystepscorresponding to the desired percentage of reduction, and the indicatorat the left-hand side of the mill will be utilized.

We have illustrated and described a present preferred embodiment of theinvention and have indicated certain modifications thereof. It will 105be understood, however, that this is by way of illustration only, andthat the invention may be otherwise embodied or practiced within thescope of the following claims.

We claim:

1. In the method of gauging the reduction of a metallic body, the stepconsisting in measuring its rate of elongation during reduction.

2. In the method of gauging a metallic body, the steps consisting inmeasuring its rate of 115 elongation during reduction, and varying theamount of reduction in accordance therewith.

3. In the method of reducing a metallic body, the steps consisting inpassing the material through a reducing means, and measuring the rate ofelongation while the material is still engaged by the reducing means.

4. In the method of rolling strip material, the steps consisting inpassing a strip to be reduced through a mill and measuring the rate ofelongation of the material while it is in the mill.

5. In the method of reducing a metallic body, the steps consisting inpassing the same through a reducing means, driving a member inaccordance with the entering speed of the material, driving a member inaccordance with the delivery speed thereof, and comparing the speeds ofsuch members.

6. In the method of reducing a metallic body, the steps consisting inpassing the same through 135 a reducing means, driving a member inaccord- .ance with the entering speed of the material,

the steps consisting in passing material back and forth through a mill,driving a member in 9. In the method of reducing a metallic body,

the steps consisting in passing it through a reducing means, driving amember in accordance with the entering speed of the material, driving amember in accordance with the delivery speed thereof, driving a thirdmember from one of such driven members at a speed which bears relationto thespeed of such driven member equivalent to a desired amount ofreduction, andsmaintaining the speed of the third member and of theother driven member the same.

10. In combination with a metal reducing apparatus, means movable atrates corresponding to the entering and delivery speeds of the materialbeing reduced, a member movable at a rate which bears a determined ratioto the speed of one of said movable means, and means for comparing thespeed of said member with the other of said movable means.

11. In combination with a metal reducing apparatus, means movable atrates corresponding to the entering and deliveryspeeds of themterialbeing reduced, 9. member movable at a rate which bears a determinedratio to the speed of one of said movable means, and means indicatingwhen said member and the other of said movable means are moving at equalspeeds.

12. In combination with a metal reducing apparatus, means'movable atrates corresponding to the entering and delivery speeds of the materialbeing reduced, a member movable at a speed related to the speed of theentering material, a member movable at a speed related to the speed ofthe delivered material, and means indicating variations in the ratio ofthe speeds of such members. I

13. In combination with a rolling mill for reducing metal, sheavesdriven by the entering and with each of said members, one member tendingto move the indicator in one direction and the other tending to move itin the other direction.

15. In combination with a metal reducing apparatus, a rotatable memberdriven at a speed related to the speed of the entering metal, arotatable member driven at a speed related-to the speed of the deliveredmetal, and means actuable by both of said rotatable members, one tendingto move the same in one direction, and the other tending to move it inthe other direction.

16. In combination with a metal reducing means,v a disc driven at aspeed related to thespeed of'the entering material, adisc driven at aspeed related to the speed of the delivered material, an arm between thediscs, and a pulley on the arm engaging a face of each disc.

17. In combination with a metal reducing.

means, a disc driven at a speed related to the speed of the enteringmaterial, a disc driven at reducing rolls and sheaves on each side aboutwhich thematerial passes, said sheaves being driven by the material, andmeans for comparing the relative speeds of the sheaves.

19. In combination with a rolling mill having work rolls and backingrolls of larger diameter, the work rolls being sufliciently small toinhibit widening of the material being rolled, means for measuring therate of elongation of. the metal.

'20. In the method of.rolling strip metal, the steps consisting inpassing the metal through rclls sufliciently small in diameter toinhibit widening of the material, and measuring the rate ofelongation-of the metal.

21. The combination with metal reducing apparatus, of means formeasuring the speed of travel of material entering said apparatus, meansfor measuring the speed of material issuing therefrom, and means forcomparing said speeds.

22. The combination with metal reducing apparatus, of means forcomparing the speed of material entering the apparatus with the speedfor indicating variations in the ratio between said speeds.

- 23. The combinationwith metal reducing apparatus," of means forcomparing the speed of travel of material entering the apparatus withthe speed of travel of the material issuing therefrom, and means forindicating variations in'the ratios of such speeds, said indicatingmeans being effective to show the direction of said variations.

24. In the method of reducing a metallic body, the steps consisting inpassing the body through a reducing means, measuring its entering anddelivery speeds, and maintaining a predetermined ratio between saidspeeds.

25. The combination with a metal reducing apparatus, of means forcomparing the length of the entering material with the length of theissuing material, and means for indicating the results of thecomparison.

26. The combination with a metal reducing apparatus, of means formeasuring the speed 01 travel of material entering the apparatus, meansfor measuring the speed of travel of material issuing from saidapparatus, and means for 'com- 130 paring said measured speeds.

27. In an apparatus for gauging the reduction of metal lengths in ametal working device, a

pair of rotatable members,' means for driving by the material leavingthe mill, a differential drive jointly actuated by said shafts, and anindicator actuated by saiddrive.

' ABRAM P. STECKEL.

HOWARD S. LAMB.

